Hopkins 47535 7 RV Blade to 6 Round Adapter With LED Tester Lightscp E Brake 7 way RV blade to 6 round Designed to create a custom plug-in simple wiring system appropriate for any towing situation The new patent-pending LED Series incorporates built-in trouble-shooting If the trailer lights are not functioning correctly, you can isolate the problem by simply looking at the adapter Universal center pin can be switched to auxiliary or electric brake